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G. A. STBPHENSON. SUSPENSION TRUSS BRIDGE (No Mdel.)

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`lantenizel Jul UNITED STATES PATENT OFFICE.

GEORGE A. STEPHENSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR OF ONE-HALF TO JOHN FRANCIS BUTLER, OF SAME PLACE.

SUSPENSION TRUSS-BRIDGE.

SPECIFICATION forming part of Letters Patent No. 479,081, dated July 19, 1892.

Application filed November 30, 1891. Serial No. 413,475. (No model.)

To all whom it may concern.-

Beit known that I, GEORGE A. STEPHENsoN, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Self Anchoring Suspension Cable- Truss for Bridges, &c., of which the following is a specification.

The object of my invention is to construct a truss of superior strength and lightness, and to so arrange and combine the several parts that it is self-contained and can be used in long spans without the necessity of anchoring v to the earth the cable which sustains it.

v beam to the head-blocks, and suitable means for sustaining the cable against the thrustbeam and head-blocks. t

My invention also comprises the combination, with the device above set forth, of an upper chord F, parallel at its mid-length with the thrust-beam and converging at the ends to the head-blocks and seated thereagainst, a series of interposed brace-blocks D', arranged between such upper chord and thrust-beam coaxial with the brace-blocks D, and suitable tension-oables G G', secured to the head-blocks and arranged to compress the upper and lower chords against the brace-blocks and draw the head-blocks against the ends of the chords.

My invention also comprises other features and combinations hereinafter more particularly set forth. s

Figure l is an elevation of a truss embodying my invention. It is shown as resting upon abutments 2. Fig. 2 is alongitudinal vertical mid-section of one end of the truss, showingthe various parts in place. Fig. 3 is a longitudinal vertical section of the other end of the i truss, showing the Various parts in place and the means I employ for tightening or straining the suspension-cable. Fig. 4. is a crosssection on line x, Fig. l. Fig. 5 is a longitudinal section showing one member of the divided straining-ferrule and showing the straining-cap or anchor-key seat and the anchor-key in section with a fragment of the end of the cable in place. 7/ y, Fig. 9, shows the line of section. Fig. 6 is an end view of a fragment of the head or straining block illustrated in Fig. 2, showing the anchorkey passed through the loop' of the cable. Fig. 7 is a longitudinal vertical mid-section of a fragment of a head or thrust block, showing a modified arrangement of the tightening or straining ferrules. Fig. Sis a plain elevation of the divided ferrule removed from the cable, the two members being slightly separated. Fig. 9 is an end View of a fragment of the head or thrust block illustrated in Fig. 3. Fig. l0 is a vertical mid-section of one of vthe section joints or unions.

The head or thrust blocks C C' are formed integral and are provided with the sockets a a', which are respectively adapted to receive the ends of the upper chord or brace-beam F and the lower chord or straining-beam B.

In practice l propose to construct the several beams and brace-blocks of metal tubes to secure the greatest strength from the material, and an opening c c is provided through each thrust-block to permit the passage of the cable E into the lower chord B. The upper chord F, thrust-beam A, and lower chord B are connected together by the interposed brace-blocks D and D', the T-joints ff', and four-wayjoints g. The brace-blocks are also tubular to secure combined strength andlightness.

My improved straining or tightening device comprises the combination of a ring-ferrule M, provided in its innerend with an annular channel m', an anchor-key resting against the outer end of such ring-ferrule and adapted to sustain the straining cable or rod E, a divided ferrule N, which is longitudinally divided into two halves m m, and is provided. upon one end with a chine n, arranged to fit in such channel m', a screw-ferruleP, arranged IOO to screw outward upon a suitable support, such as the thrust-beam A, and provided upon its outer end with an annular nut or head P' having an annular channel O arranged to receive the inner end of the divided ferrule, and the straining cable or rod E, secured at one end to the anchor-key and extending" through the ring-fcrrule, divided ferrule, screw-ferrule, and support.

The straining or supporting cable E is provided on one end with a loop e, which is formed by bending the cable upon itself and splic ing, as illustrated in the drawings. The end, which is passed through the block C, is secured by a key II, which rests in notches 7L, provided in the end of the ferrule I, which is screwed or otherwise secured upon the end of the thrust-beam which passes through and projects beyond the head-block C.

The cable E passes into `the end of the thrust-beam A and then passes through the hole 'L' in the bottom of the thrust-beam, and thence through a hole c in the thrust-block C and into the inside of the tubular strainingbeam or lower chord B, along which it passes to the opposite end thereof, and then through the holes c and i and into and outof the end of the thrust-beam A, and is there `provided with a loop e', through which is passed the anchor-key IJ, which rests in the notches h, provided in the ring-ferrule M.

Q is an adjusting ferrule or collar, which is screwed upon the thrust-beamA and arranged to engage the head-block to equalize the strain against the head-block C and the said thrust-beam.

In Fig. 7 I have shown the adjusting ferrule or collar Q provided with external threadi ing and the screw-ferrnle P screwed upon the exterior thereof to give greater strength of construction; but I do not limit my claim to any specific form of construction of the screwferrule and adj usting-ferrule.

The object of passing the thrust-beam A entirely through the tbrusbblocks C C' and passing the straining-cable E through the holes c c and t i `into the tubular thrustbeam is to bring the `thrust of the cable di rectly in line with the axis of the thrust-beam.

The ferrule-collar `Q, screwed upon the end of thrust-beam A, is designed to be screwed up against the thrust-block as the cable is tightened, thus to assist in equalizing the strain and throw a part of it upon the beam and a part upon `the head-block.

In Fig. 2 I have shown the `thrust-beam and upper and lower cords F and B reinforced where they enter the head-block C by means of the auxiliary socket-sections ot' pipe 1, fitted upon the exterior' of said beams and into the head-block C. The object of this is to strenghten the beams at these points to prevent them froni bending when the strain is placed upon the head-blocks.

In practice the cable E is passed through the ends of the thrust-beam and through the lower chord before the loop e is formed and before the divided ferrule N is placed in po sition. The loop e is then drawn into the ferrule I until its further passage is prevented by the end of the thrust-beam A. This allows the opposite end of the cable to project far enough beyond the end of the ferrule P to enable the end of the cable to be spliced upon itself to form the loop e. When this is done, the loop e is drawn back until it projects beyond the ferrule I, and the key II is passed through said loop and placed in the notches h in the ferrule I. The loop e is then drawn outward until the cable E is taut. Then the ring-ferrulelvl is passed over the end of' the loop e and the anchor-key L is passed through such loop and placed in the notches h in the ring-ferrule M, which is then drawn outward against such anchor-key to allow the divided ferrule to be placed in position between the ring-ferrule and the screw-ferrule P, which had previously been screwed upon the' thrustbeam A until it engages the collar-ferrule Q. vThe two halves of the divided ferru-le N are then placed with their inner `ends resting in the channel O in the head of the screw-terrule P and the chine of their outer ends resting in the annular channel m in the `ring-ferrule M. The screw-ferrule Pis then screwed outward, thus `forcing the. divided `ferrule and the ring-ferrule with the anchor-key L outward to tighten the cable E by the thrust against the beam A. To keep this beam rigid, I employ the tension-cables G G,which are arranged as shown" in the drawings. This arrangement is practically described and claimed by `me `in Patent No. 468,841, dated February 16, 1892,1or elevated-railway structure, and I lay no claim thereto in this specification.

In practice in bridges of short spans designed forliglrt traffic the upper chord F may be only of sufficient height for a railing for the bridge, or it may be entirely omitted in some cases. In case it is deemed desirable the lower chord B may be lled with melted bituminous material after the cable has been tightened, and thus gives perfect protection from atmospheric action upon the cable.

New, having described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. In a truss, the combination set forth of the thrust-beam, the tubular lower chord converging thereto at the ends, two thrust or head blocks arranged, respectively, at the points of convergence of the thrust-beam and the lower chord to seat the ends thereof, a series of interposed brace-blocks arranged between the lower chord and the thrust-beam, the suspension-cable extending through the lower chord and through the head-blocks, means for securing such cable and thrustbeam to the head-blocks, and suitable means for straining the cable against the thrustbeam and head-blocks.

2. The truss set forth, comprising the cornbmation of the thrust-beam, the tubular lower ICO IIO

chord converging thereto at the ends, two thrust or head blocks arranged, respectively, at the points of convergence of the thrustbeam and the lower chord to seat the ends thereof, a series of interposed brace-blocks D, arranged between the lower chord and thrustbeam, the suspension-cable extending through the lower chord and through the head-block, suitable means for straining the cable against the thrust-beam and head-blocks, the upper chord parallel at its mid-length with the thrust-beam and converging at its ends to the head-blocks and seated thereagainst, a series of interposed brace-blocks D', arranged between such upper chord and the thrust-beam` thereof, the interposed brace-blocks, the suspension-cable passing through the lower chord and thrust-blocks and provided with a loop at each end, the adjusting-ferrule screwed upon the end of the thrust-beam and arranged to engage the head-blocks, the ring-ferrule, the anchor-key passed through the loop of the cable and arranged to rest against the ringferrule, the screw-ferrule screwed upon the end of the thrust-beam, andthe divided straining-ferrule arranged between the screw-ferrule and therring-ferrule. Y

4. The combination of the ring-ferrule pro- .vided in its inner endwith the annular channel, the anchor-key arranged to rest against the outer end of such ring-ferrule, the divided .'errule provided on oneend with the chine arranged to fit in such annular ehannehthe screw-ferrule provided kwith the annular chan- -nelrarranged to receive the other end of the divided ferrule and arranged to screw upon a suitable support, and the straining-cable secured .to the anchor-key and extending through the ring-ferrule, divided ferrule, and screW-ferrule. Y

5.V In a truss of the class described, having lthe screw-ferrule and the ring-ferrule, as set forth, tliedividedferrule N, arranged between the screw-ferrule and ring-ferrule.

GEORGE A. STEPHENSON Vitnesses:

JAMEs R. .TowNsENu ALFRED I. ToWNsEND. 

